OKLAHOMA CITY (AP) -- The Oklahoma Geological Survey is investigating whether work done by an oil and gas company may be the cause of recent earthquakes in the Midwest City area.
Eight quakes ranging from 1.3 to 3.0 magnitude have been recorded in the area since December. Before that only nine earthquakes have been recorded in the region in the past 29 years.
Geological Survey director Charlie Mankin says New Dominion LLC has been taking saltwater and oil in the area then injecting leftover saltwater back underground near a fault zone.
He says similar injections have been known to cause earthquakes.
But he says there's no clear-cut evidence what the cause is and that it may simply be a natural build-up of stress along the fault line.